[Fullvolume]

What is the minimum amount of open space an amp should have in order to 'breathe'.
I what to place 2 7B's one on top of the other with maybe a spacer of some sorts or is this a bad idea all together.

[Levi]

I would say at least several inches.  I had mine stacked before and works fine.  Currently, I have mine as close to the speakers as possible using short speaker wires to take the advantage of having mono amps.


Stacked 7B

[James Tanner]

Generally 1 3/4 inches is considered adequate as long as there is reasonable air circulation around the amps.

james

[Napalm]

How about stacking them side by side in vertical position? (i.e. rotate the previous pic 90 degrees)

Nap. 

[srb]

How about stacking them side by side in vertical position? (i.e. rotate the previous pic 90 degrees)

The vertical heat sinks are designed for bottom to top convection air flow through the fins.  I'm sure it would work, but I have to think that would be less than optimal orientation.
 
Steve

[James Tanner]

The vertical heat sinks are designed for bottom to top convection air flow through the fins.  I'm sure it would work, but I have to think that would be less than optimal orientation.
 
Steve

Correct - the heat sinks are designed to act like a convection chimney - in fact the heat sinks are computer modelled to provide as much efficiency and heat dissipation as possible.  Even changing the space between the fins a little will cause a loss of about 15% efficiency.

James